Selektivitätssteigerung katalytischer bestimmungsverfahren—extraktionskataly-metrische molybdänbestimmung

To increase the selectivity of catalytic methods, a solvent extraction and catalytic determination have been combined. By means of the determination of molybdenum based on the catalytic oxidation of 1-naphthylamine by bromate, it is shown that by selection of a suitable extraction system the catalyst can be determined directly in the organic extract. The catalytic activity of different complexes of molybdenum was tested and for an analytical application the extraction of molybdenum as oxinate was chosen. The method enables molybdenum to be determined down to 2.7 × 10^?9M. The relative error of the determinations is 10%. 10^?4M V, 2 × 10^?4M Cr, 5 × 10^?5M W and 10^?2M Mn, Ni, Cu, Co, Fe, Mg, Zn, Cd, Al and Pb cause no interference. The method has been used for the determination of molybdenum in sea-water.